Method of actuating machines such as a tilting device for ingots



G. A. JEAN MARIE MARTELEE 3,456,823 METHOD OF ACTUATING MACHINES SUCH AS A TILTING DEVICE FOR INGOTS July 22, 1969 Filed June 15, 1967 Gm LA 0/ .4I/I0/Nt' Jew Mew/i Mira 55 United States Patent Oflice Patented July 22, 1969 Int. cl. B6s 65/24 U.S. 'Cl. 214152 1 Claim ABSTRACT OF THE DISCLOSURE For the manipulation and transport of commercial and industrial products and particularly for tilting of ingots there are known various devices and apparatuses actuated by driving means; the invention concerns a method for actuating such a device in which the gravity energy engendered by the descent of a loaded element is accumulated and then used to bring back the unloaded element to its initial position; in a tilting device for ingots a basket loaded with an ingot is rocked about a horizontal axis and compresses gas lodged in a chamber so as to recuperate the gravity energy of the descent of the loaded basket which after unloading of the ingot is returned back to its initial position by expansion of said compressed gas.

This invention relates to a method of actuating a machine such as a tilting device for ingots.

It is known that the manipulation, transport or change of place or position of commercial and industrial products, is undertaken with the help of various devices or apparatuses actuated by driving means of different types, particularly motors, whose power depends on the operations to be carried out and on the weight of the products to be manipulated.

Particularly, for certain metallurgical operations, such as rolling, the ingots must be disposed in the longitudinal direction while they are drawn vertically from the reheating furnaces; in order to put them into this horizontal position, there have been conceived tilting devices for ingots, which are apparatus essentially composed of an ingot support basket mounted on pivots and rockable around a horizontal axis situated below the centre of gravity of the whole of the basket and ingot, and outside of the vertical passing through the centre of gravity; this placing is necessitated by the bank of transport rollers at the rolling mill in conventional installations. The known tilting devices are driven in their pivoting by a continuous motor of very high power, taking into account the weight of the tilted ingots; in these tilting devices, in particular the starting efforts are very considerable and the motor requires a feed, whose current peaks are very high and which, resulting from this fact must be made by Ward-Leonard groups or by rectifiers. The result of this is that the known tilting devices are costly, not only to install but also in functioning.

The problem at the basis of the invention is to do away with the external feed of the driving means of a handling apparatus, making a product to pass from a higher level to a lower level and to make the said apparatus function only by the energy recuperated during the descent.

The invention concerns a method of actuating a machine in which an adjustable element following a guiding element is provided with a load and descends freely between an upper and lower level under the action of the weight and is brought back to the upper level after removal of the load, being characterized in that the gravity energy engendered by the descent of the adjustable loaded element is used to put under pressure a compressible fluid, the potential energy of which thus accumulated is then used by a cut-off to bring back the unloaded element to the upper level, where it can receive another load in such a way as to repeat indefinitely the operations of descent of the adjustable loaded element and of the return to the initial level of the unloaded element.

In accordance with one feature of the invention, the compressible fluid, which is preferably an inert gas such as nitrogen, is previously introduced under very high pressure into the first tight chamber in order to place all the hydraulic system under pressure; in accordance with a modification, the pressurization of the inert gas is brought about by the descent of the first ingot, the operations of raising the empty basket and descent of the loaded basket being repeated then indefinitely.

The invention will now be described in greater detail by way of example with reference to the accompanying drawing, in which:

FIGURES 1, 2 and 3 are diagrammatic views showing an elevation of a lateral face, an elevation of the rear face, and a plan respectively of a tilting installation embodying the invention.

The installation as shown comprises a basket 1 provided with two lateral pivots 2, disposed in alignment with a horizontal axis which comprises the axis of pivoting of the basket; this axis is situated at a level lower than the centre of gravity of the basket I loaded with an ingot 3 and is disposed in front of the vertical passing through the centre of gravity with relation to the direction of pivoting. The pivots 2 turn in bearings 4, supported by a rigid frame 5, resiliently mounted on helicoidal springs 5a. At the beginning, the basket I loaded with the ingot 3 rests on stops 6 at the rear of the frame 5.

On the end of the two lateral pivots 2 are fixed arms 7, to which are articulated links 8 which in turn are articulated to pivoting levers 9 which in turn are articulated to the ends of rods 10 of the pistons of hydraulic jacks 11a and 11b pivotably mounted at 12C and 12d respectively between yokes 12a and 12b and the frame 5 on one side and the other of the latter.

The rocking of the basket is effected by a hydraulic system which will now be described.

A cylindrical accumulator 13 contains in a first closed chamber 13a an inert gas, such as nitrogen, previously compressed to a very high pressure which can be 150 to 200 kg./cm. A movable piston 13b separates this first chamber from a second closed chamber which is filled with oil.

The chamber 13C is attached to a pipe 14 having two pipes 15a and 15b coming from it.

The pipe arrives at a sliding electro-valve for changing the directions 16a at which terminate also pipes 17a, 18a and 19a respectively attached to the front chamber and to the rear chamber of the jack 11a and to an oil reservoir 20; in the pipe 17a are disposed a diaphragm 21a, a one-way check valve 22a from which come two pipes 23a and 24a provided one with a diaphragm 25a and the other with a one-way check valve 26a; these two pipes 23a and 24a also end in the reservoir 20.

The pipe 15b arrives at a sliding electro-valve for changing the direction of flow 16b at which terminate also pipes 17b, 18b and 19b attached to the front chamber and to the rear chamber of the jack 11b and to the reservoir 20 respectively; the pipe 18b being provided with a one-way check valve 22b and is also connected to the reservoir 20 by a pipe 24b in which there is a oneway check valve 26b; a diaphragm 25b is disposed in a pipe 23b joining the pipe 18b to the pipe 19b.

' After assembling of the installation, there is effected the filling of the hydraulic system, from which air is expelled by purging and nitrogen is introduced under a very high pressure in chamber 131: of the accumulator,

3 the spring-return electro-valves 16a and 16b being at rest in the positions shown in FIGURE 3.

The pressure of the oil coming from the accumulator 13 is without any effect on the jack 11a because the pressure of the oil in the chamber 13c passing by the pipes 15a and 17a is stopped by the one-way check valve 22a and also on the jack 11b because the oil pressure in the chamber 13c passing by the pipe 16b is stopped by the one-way check valve 22b.

At the start of an operation the basket 1 rests on the stops 6; an ingot 3 is disposed in the basket 1 by means of a rolling bridge. By the activation of a pushbutton (not shown) in an electric circuit (not shown), the electro-valve 16b is excited and moved towards the base against the action of its return springs; due to this, through the pipes 14, 15b the electro-valve 16b and the pipe 17b, the pressure of the oil in the chamber 130 acts on the front chamber of the jack 11b whose piston is pushed back following the direction of the arrow X. In this way by the set of rods 7, 8, 9 and 10, the jack 11b makes the loaded basket 1 pivot in a counter-clockwise direction. The loaded basket 1 leaves the stops 6 and pivots progressively until the centre of gravity of the whole, basket and ingot, is slightly beyond or outside the vertical V passing through the axis of pivoting; at this moment a contact breaker (not shown) automatically cuts the current to the electro-valve 16b which is maintained excited by the action of the push button (not shown) and as soon as the current is cut the electro-valve returns to its position of rest by the action of its return spring.

In the course of this operation, the nitrogen is expanded and the piston 13b occupies its position 13b; the electrovalve 16b being returned to the designated position thus puts the pipe 171) into communication with the pipe 19b and the pipe 181) with the pipe 15b. Thus, the front of the jack 11b is in contact with a reserve of oil in the reservoir 20 and the rear of the jack 11b is connected with the chamber 13c by means of the check valve 22b and with the reservoir 20 by the diaphragm b and the pipes 23b and 19b. The loaded basket having passed the vertical, descends under the action of the weight and by the arms 7, the links 8, and the levers 9, drives the pistons of the jacks 11a and 11b, still following the arrow X; the jack 11b sucks oil out of the reservoir 20 and propels some towards 18b and 1515; a small part of this oil is sent to the reservoir 20 by the diaphragm 25b and the remainder driven towards the accumulator 13, serves to recompress the nitrogen in the chamber 13a by re-pushin-g the piston 13b towards the right. By the descent of the loaded basket 1, the jack 11a is driven like the jack 11b; the oil propelled by the jack 11a leaves by the pipe 18a and by the pipe 19a arrives in the reservoir 20 which is at atmospheric pressure. When the pressure of the nitrogen in the chamber 13a has become sufiicient to equilibrate the action of the loaded basket, the latter lessens in speed a little before the end of the pivoting, the oil propelled by the jack 11b continues to pass by the calibrated diaphragm 25b and goes to the reservoir 20 by the pipe 19b. Thus, due to the rate of leakage, the loaded basket continues to descend very slowly by its weight until it finally comes to rest on the front stops 23, in such a way that the ingot 3 rests only on the transporting rollers 24. The cross pieces 1a of the basket 1 being completely disengaged, the transport rollers 24 are set into rotation and the ingot is removed. When the basket is empty, it can be returned by exciting the electro-valve 16a by a push button (not shown); this electro-valve 16a moves towards the base, thus interconnecting pipes 15a and 18a as well as pipes 19a and 17a. The pressure of oil of the accumulator 13 acts by the pipes 15a, 16a and 18a and pushes the piston of the jack 11a back again in the opposite direction to that of the arrow X; whilst the oil propelled by the front of the jack 11a passes by the pipes 17a, 22a, 21a and enters into the reservoir 20. The basket 3 is raised by the action of the jack 11a; during this operation the two faces on the piston of the jack 11b drawn by the movement of the basket are in contact with the reservoir 20 by the pipes 17b, 19b and electro-valve 16b, which is in the designated position; the check valve 261; is open, since the oil is sucked in out of the reservoir 20 by the back of the jack 11b, whose front propels the oil towards the reservoir 20 by passing through pipes 17b, 16b and 19b. The centre of gravity of the empty basket approaches the vertical of the axis of pivoting and a circuit breaker (not shown) automatically cuts the excitation of the electro-valve 16a which returns to the shown position; the empty basket pivots towards the rear by inertia and by its own weight; the jack 11a draws in, through the back, oil from the reservoir 20 by pipes 18a and 19a, and by the front, it expels some oil which tends to pass through the diaphragm 25a to arrive in the reservoir 20. A part of this oil passes through the check valve 22a, the diaphragm 21a, the pipe 17a, electro-valve 16a, and the pipe 15a in order to compress the gas in the chamber 13a. The basket is braked in its descent by the increase of pressure of the gas in chamber 13a of the accumulator 13, but it continues to descend, taking into account that the oil passes through the constriction 25a and enters into the reservoir 20. The basket thus returns to its starting position where it rests on the stops 6 and the cycle of operations can start again when the basket is loaded with another ingot.

What I claim is:

1. A method of actuating a machine, comprising positioning a movable element in stable equilibrium at an upper level, loading said movable element with a weight while maintaining said movable element in said stable equilibrium, expanding a compressed gas in a chamber, applying the force of said expanding gas to hydraulic oil in two hydraulic jacks, swinging said movable element under the influence of said jacks about a horizontal axis until the center of gravity of said movable element and said weight crosses the vertical plane that includes said axis, lowering said movable element and weight to a lower level under the action of gravity while applying the force of the descending movable element and weight through said jacks and said oil to recompress said gas in said chamber, directing some of said oil to a reservoir at atmospheric pressure, removing said weight from said movable element, expanding said compressed gas in said chamber, applying the force of said last-named expanding gas to said oil and jacks to raise said movable element to an upper unstable position in which its center of gravity again crosses said plane, and lowering said movable element to said stable equilibrium starting position.

References Cited FOREIGN PATENTS 1/1960 Great Britain.

US. Cl. X.R. 

